Artificial leg



Feb. 17, 1942.

5. J. DEW

ARTIFICIAL LEG Filed Jan. 15, 1941 a. w. I

Patented Feb. 17, 1942 V UNITED STATES PATENT OFFICE ARTIFICIAL LEG Stanley J..Dew, Toronto, OntaridCanada Application January 15, 1941, Serial No. 374,445

6 Claims.

This invention relates to artificial legs, which are intended for use in the case of a Symes amputation, that is, a case where the forward part of the foot including the ankle bone is re moved and the heel part is bent forward and allowed to knit to the leg stump to form a base therefor. To facilitate walking, it is necessary therefore to include in the artificial leg the equivalent of an ankle joint. The artificial leg must of necessity be firmly secured to the real leg, but with artificial legs as heretofore constructed it has been found that they have a tendency to break, and further, they are very tiresome on the shin portion of the real leg.

The object of my invention is to devise an improved artificial leg which will give the necessary support, which will avoid this tendency to break, and which will provide a limited amount of freedom for the shin, thus avoiding the tiresome effect on the latter.

I attain my object by means of the construction described and illustrated in the accompanying drawing in which Fig. 1 is a side elevation, partly broken away, of the improved leg;

Fig. 2 a front view of the same, also partly broken away;

Fig. 3 a section on the line 3-3 in Fig. 1;

Fig. 4 a section on the line 44 in Fig. 2;

Fig. 5 a detail in side elevation illustrating a modified form of hinge; and

Fig. 6 is a front view of the same.

In the drawing like numerals of reference indicate corresponding parts in the different figures.

The improved leg comprises a leg portion A having a foot portion B pivotally connected together, and it is with the leg portion with which the present invention is particularly concerned. The leg portion comprises a metal base I from which extends a leg support 2. The base and support, are preferably formed as an integral casting of any light metal such as aluminum. The support 2 in transverse cross section is shaped to extend from a position at one side of the front of the leg, rearwardly around the back of the leg and then forwardly to a position at the other side of the leg, thus encasing all but the front of the leg. I

The interior of the base is shaped to form a socket for the stump of the leg, as will be seenin Fig. 4.

Within the metal casting is fitted a sheath 4 of leather or other suitable material. This sheath is shaped to perfectly fit the leg, and in turn in moulding the metal casting a form is employed which corresponds as close as possible with the leg with the leather sheath fitted thereon, so that a very close fit is obtained in the finished leg. l

It is important that there is no relative movement between the leather sheath and the casting, and the leather sheath is therefore secured in place by a strong adhesive, and further the leather sheath and metal casting are secured in place by rivets 5 adjacent the forward edge of said metal casting. Rivets may also be used at the rear if desired to hold the sheath and casting together.

The leather sheath is divided at the front and is provided with a series of holes 6 at each side of the opening for lacing purposes.

A tongue l4, preferably padded, is secured within the sheath to protect the shin from chafing by the laces.

It will thus be seen that the leather sheath and metal leg casting form substantially a unitary construction, and, having been made to fit a form corresponding to the leg, will firmly support the leg. The front of the leg portion has a limited amount of flexibility due to the use of leather only at this point, and thus avoids chafing of the shin bone.

The foot B may be secured to the leg A in any suitable manner.

In the form shown in Fig. 1, a plate I is secured to the under side of the base, which plate carries a transversely directed pivot tube 8 in which is mounted a pivot member 9, from which depends a connecting rod I0 which extends through the foot ll proper. Resilient cushions l2 and 13 are interposed between the foot and base to hold the foot in normal position,

In Fig. 5 a modified pivot arrangement is shown. In this case a U-shaped connecting member Ill is fitted over the pivot member 9*.

It will be apparent, however, that I do not desire to limit myself to any particular form of pivot for the foot connection.

It will be seen from the foregoing description that I have devised an artificial leg which will provide firm support for the leg stump at the back and sides, thus avoiding the objectionable chafing of the'front of the stump. As the casting firmly supports the leather sheath, it will be seen that the leather sheath is always firmly maintained in proper shape, thus avoiding trouble such as encountered in legs of the old type in which the leather sheath often became deformed due to the continuous flexing, erspiration or other causes.

What I claim as my invention is:

1. In an artificial limb for use with a Symmes amputation, a shank-encasing member comprising a base having a stump-receiving socket formed in its upper side; an open-fronted support forming an upward extension of the rear and sides of said socket for supporting the rear and sides of the calf of the leg; a tubular shank sheath secured in said open-fronted support; and an artificial foot member pivotally connected with the base. I

2. In an artificial limb for use with a Symmes amputation, a shank-encasing member comprising a base having a stump-receiving socket formed in its upper side; an open-fronted support integral with and forming an upward extension of the rear and sides of said socket for supporting the rear and sides of the calf of the leg; a tubular shank sheath secured in said open-fronted support; and an artificial foot member pivotally connected with the base.

3. In an artificial limb for use with a Symmes amputation, a shank-encasing member comprising a base having a stump-receiving socket formed in its upper side; an open-fronted support forming an upward extension of the rear and sides of said socket for supporting the rear and sides of the calf of the leg; a tubular shank sheath secured in said open-fronted support; means for securing said sheath and support to prevent relative movement between the contacting parts of their surfaces; and an artificial foot member pivotally connected with the base.

4. In an artificial limb for use with a Symmes amputation, a shank-encasing member comprising a base having a stump-receiving socket formed in its upper side; an open-fronted support forming an upward extension of the rear and sides of said socket for supporting the rear and sides of the calf of the leg; a tubular shank sheath secured in said open-fronted support, the exposed front of said sheath being divided; fastening means for the divided front of the sheath; and an artificial foot member pivotally connected with the base.

5. In an artificial limb for use with a Symmes amputation, a shank-encasing member comprising a base having a stump-receiving socket formed in its upper side; an open-fronted support integral with and forming an upward extension of the rear and sides of said socket for supporting the rear and sides of the calf of the leg; a tubular shank sheath secured in said openfronted support, the exposed front of said sheath being divided; fastening means for the divided front of the sheath; and an artificial foot member pivotally connected with the base.

6. In an artificial limb for use with a Symmes amputation, a shank-encasing member comprising a base having a stump-receiving socket formed in its upper side; an open-fronted support forming an upward extension of the rear and sides of said socket for supporting the rear and sides of the calf of the leg; a'tubular shank sheath secured in said open-fronted support, the exposed front of said sheath being divided; fastening means for the divided front of the sheath; means for securing said sheath and support to prevent relative movement between the contacting parts of their surfaces; and an artificial foot member pivotally connected with the base.

STANLEY J. DEW. 

